Around 1741, Bach (then at his mid 50s), published a long and complicated music piece for piano, called Aria. Aria is a beautiful and simple melody which inspires 30 inventive variations which follow. These variations are improvisations of the main music theme developed in Aria, revolving around this theme and integrating changes in harmony, melody, orchestration, tempo and many other factors.
The variations were probably named after Johann Goldberg who was a very skilled keyboardist, although a teenager, and was probably the first person who performed them. Performing this music is a challenge as it requires virtuoso playing and infallible coordination as the hands frequently cross each other while playing the piano.
In 1955, the 22 year old pianist Glenn Gould performed the Goldberg Variations in a very fast but precise way, by shrinking the score to only 39 minutes (from 1 hour that it normally takes).
The structure of the total work is very intricate, reflecting Bach's obsession with mathematical principles and numerology. There is a complex logic behind this structure. The rationale behind this masterpiece is about generating a large number of replications based on a single piece of code. Its inventiveness and architecture is probably at the level of a complex human achievement, while its music is dazzlingly beautiful. As John Keillor, a music critic writes: "The work is sublime and compassionate, graceful, warm and relentlessly intricate, a demonstration of unmatched craft in music history and genuine, poetic imagination"